Pressure operated lift

ABSTRACT

A vertically adjustable power lift incorporating a wheel mounted U-shaped base frame and a similarly configured load-supporting top frame mounted thereover for vertical adjustment by means of an articulate cross link unit. Pulley guided cables extend from the articulate unit to a controlled power unit for a control of the raising and lowering of the top frame and load.

United States Patent [191 Klassen et al.

[ Oct. 9, 1973 PRESSURE OPERATED LIFT [76] Inventors: Laverne M.Klassen; Doris V. Frost,

both of 114 W. Main, Turlock, Calif. 95380 22 Filed: Dec. 7,1971

21 Appl. No.: 205,653

[52] US. Cl 254/8 R [51] Int. Cl. B60p 1/48 [58] Field of Search 254/4R, 4 BC, 8,

254/9, 10 R, 10 13,10 C, 2 R, 2 B, 2 C, 93 R, 122, 124, 126, 127;214/390; 187/18 [56] References Cited 7 UNITED STATES PATENTS 2,487,50811/1949 Anderson 214/390 1 2,937,003 5/1960 Croll 254/93 R 2,830,8544/1958 Cottar 254/9 C FOREIGN PATENTS OR APPLICATIONS 138,168 2/1949Australia 254/4 R 831,541 3/1960 Great Britain 254/10 C PrimaryExaminer-Othell M. Simpson Assistant Examiner-Robert C. WatsonAttorney-Harvey B. Jacobson et al.

[57] ABSTRACT I A vertically adjustable power lift incorporating a wheelmounted U-shaped base frame and a similarly configured load-supportingtop frame mounted thereover for vertical adjustment by meansof anarticulate cross link unit. Pulley guided cables extend from thearticulate unit to a controlled power unit for a control of the raisingand lowering of the top frame and load.

8 Claims, 4 Drawing Figures Patented Oct. 9, 1973 2 Sheets-Sheet 1 2Sheets-Sheet 2 PRESSURE OPERATED LIFT The present invention is generallyconcerned with a power operated lift utilizing a controlled hydraulicsystem. More particularly, the invention is directed to a lift uniquelyadapted for use in bakeries, schools, hospitals, and the like for thehandling of large mixer bowls, sacks of flour, and similar heavy loads.

[t is a primary object of the invention to provide a lift which isspecifically adapted for the handling of large kitchen or bakeryequipment and supplies for a movement thereof as required including thepositioning of mixer bowls on dollies and scales and the removal of themixer bowls therefrom, the lift also enabling a raising of the mixerbowls to any convenient working height.

In conjunction with the above object, it is a significant object of theinvention to provide a lift uniquely adapted, through an open endedconfiguration, to straddle mixer bowls or the like for an engagementwith the sides thereof in a manner which leaves the bottom of the mixerbowl free for depositing on dollies, scales, and the like, as well as asimiplified removal therefrom.

Further objects of the invention include the provision of a lift whichis compact, highly mobile and easily operated.

Basically, the lift includes a wheel supported base frame mounting a topframe thereover through selectively extensible and collapsiblescissors-type linkages.

The linkages are controlled through pulley guided cables operativelyconnected to a pressure actuated piston rod.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout and in which:

FIG. 1 is a top plan view of the lift comprising the instant invention;

FIG. 2 is a side elevational view of the lift in its collapsed position;

FIG. 3is a side elevational view of the lift in its extended position;and

FIG. 4 is a rear elevational view of the lift.

Referring now more specifically to the drawings, reference numeral isused to generally designate the lift comprising the invention. The lift10 includes a base frame 12 of a generally U-shaped configuration,incorporating a pair of laterally spaced side rails 14 rigidlyinterconnected by a transversely extending back rail 16, defining anopen forward end which allows for a straddling of -a mixer 18 or thelike.

The base frame 12 mounts on four swivel rollers 20 secured to anddepending from the opposed ends of the two side rails 14.

A top frame 22, of the same general configuration as the base frame 12,isprovided in parallel overlying relation to the base frame 12. This topframe, including laterally spaced side rails 24 and atransverselyextending rear rail 26 likewise defines an open forward endfor a straddling of the load.

The load is to be directly supported on the top frame 22 with this frame22 being vertically adjustable relative to the base frame 12 for aselective raising or lowering of a load. The top frame 22 and base frame12 are and 12. The upper and lower forward link ends are respectivelyreceived between frame rail mounted tracks 32 for a sliding retention oflink and mounted cross pins 34. Each of these pins 34 can, if sodesired, have appropriate slides or rollers mounted on the trackconfined outer extremities thereof. This sliding movement of the forwardends of the upper and lower links 28 allows for the free expansion andcollapsing of the scissor frames 26 and a corresponding verticaladjustment of the upper frame 22.

The power controls for the lift 10 are mounted primarily on the rearrail 16 of the base frame 12 and include a fluid reservoir 36, a pump 38and a hydraulic cylinder 40 having an outwardly directed piston rod 42through the pump lever 46 and pressure release 48 is in itselfconventional. Of particular interest with regard to the fluid reservoir36, pump 38 and ram unit 40 and 42 j is the compact longitudinalorientation thereof along the rear rail 16, maintaining the interior ofthe lift free of interfering projections or the like, while at the sametime providing only minimal rail projection, such rail projection infactbeing no greater than that of the vertical lift manipulating handle 50.The handle 50, as

. will be noted from the drawings, consists of an elevated cross barintegrally formed with apair of depending side posts, the lower ends ofwhich are rigidly affixed to the opposed end portions of the rear baseframe rail 16.;

In order to transmit the movement of the piston rod 42 to acorresponding movement of the scissor frames 26, a pair of elongatedcontrol cables 52 and 54 are provided. The cables 52 and 54 are affixedto the opposed ends of the rod crosshead 44 and extend toward a firstend of the rear rail 16 and about a pair of bracket mounted pulleys 56and 58.'The cable 52 extends from the pulley 56 forwardly and upwardlyalong the adjacent side rail 14 for engagement over an elevatedvertically orientated post mounted pulley 60. generally aligned with andslightly outward of the central portion of the adjacent scissorsframe'26. The cable 52 extends downwardly beyond the pulley 60 and ispivotally affixed to a bracket 62 mounted on one of 'the links 28 in amanner whereby'a tensioning of the cable 52, I

through an extension of the rod 42' will effect an up ward drawing ofthe link mounted bracket 62 and a corresponding upward swinging of thepivotally interconnected remaining links. As indicated, the positioningof the pulley 60 is effected through a vertically elongated post 64afiixed to the outer face of the corresponding side rail '14.

The second cable 54, after passing about the first end mounted pulley58, extends generally parallel along the rear rail 16 and about a secondbracket mounted pulley 66 positioned at the second end of the rear rail16. The cable 54 then extends forwardly and upwardly along the secondside of the base frame 12 for engagement over an elevated post mountedpulley 68 similar to and opposed from the pulley 60. The cable 54 thenextends downwardly for pivotal engagement with a. link mounted bracketon the second scissors frame 26 for an operation thereof in the mannerpreviously described in conjunction with the cable 52.

The control system, constructed as above, provides an equal lifting loadon the two opposed scissors frames to insure a level operation of thelift with the lifting force being applied along the opposed loadreceiving side rails 24 of the top frame 22. If so desired, appropriatecable length adjusting means can be utilized, note for exampleturnbuckle 70.

With reference to FIG. 1 in particular, in order to adapt the top frame22 to various size mixers and the like, a pair of opposed hinge mountedplates 72 are mounted on the two top frame side rails 24 for engagementbeneath pot or mixer flanges, lifting lugs or han dles. Each of theplates 72 includes an upwardly projecting stabilizing or positioning lug74. Further, in order to lock the received mixer, pot or the like on thetop frame, a pivotally mounted holding arm 76 is mounted centrally onthe top frame cross rail 26 for selective orientation into a retainingposition.

From the foregoing, it will be appreciated that a compact highlyversatile power lift has been devised. The lift, through the dualscissor frames, eachindividually cable controlled, provides a positivebalanced lift action. In addition, the open front of the liftparticularly adapts it for stradling large mixers, pots, kettles and thelike for a raising, carrying and lowering thereof without necessitatingany manual manipulation of the'mixer in either the loading or unloadingthereof onto the lift or from the'lift. Incidentally, while the lift isparticularly adapted for straddling and liftingg mixers and the like, itcan also be easily adapted'for the accommodation of bulk loads such assacks of flour or the like. All that is required is the positioning ofan inverted baking pan onthe top frame, a locking of the pan by theholding arm 76 and a vertical adjustment of the lift to bring the framesupported pan to the level of the sack or the like. The sack is theneasily horizontally shifted onto the pan and from that point on powercontrolled by the lift mechanism.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications andtween thespaced side members, said extension frame comprising two sections, eachsection extending vertically between the corresponding side members ofthe base frame and the top frame and defining an open article receivingarea between the side members, a power unit mounted between the sidemembers of the base frame opposed from the side member defined open end,and force transmitting means engaged between the power unit and eachextension frame section for effecting a powered control thereof, eachextension frame section being of a scissor-type crossed linkconstruction, said power unit including a selectively extensible andretractable hydraulically controlled piston rod, the force transmittingmeans comprising a pair of cables fixed to the piston rod, each cableextending from the rod to one extension frame section, and pulleysguiding each cable.

2. The lift of claim 1 wherein one pulley associated with each cable ismounted adjacent the corresponding extension frame section generallycentrally thereof and at an elevated position relative to the baseframe, the associated cable extending over this one pulley and downwardinto engagement with a link of the section located therebelow whereby atensioning of the cable will effect a raising of the engaged link and acorresponding extension of the section and raising of the top frame. I

3. The lift of claim 2 including wheel means mounted on said base frameand depending therefrom for rolling engagement with the ground. 4

4. A power lift comprising a base frame and a top frame in overlyingparallel relation to said base frame, an extension frame between saidbase frame and said top frame, said extension frame mounting said topframe for vertical adjustment relative to said base frame, saidextension frame comprising a pair of laterally spaced verticallyorientated scissor-type crossed link sections, a power unit mountedtransversely across said base frame, said power unit including aselectively extensible and retractable hydraulically controlled pistonrod, and a pair of cables fixed to said piston rod for control thereby,each cable extending from said rod to one of said extension framesections, and pulleys guiding each cable between the piston rod andsection, one

spaced side members defining an open end forthe reception of articles tobe lifted therethrough and be- ,pulley associated with each cable beingmounted adjacent the corresponding extension frame section gener allycentrally thereof and at an elevated position relativeto the base frame,the associated cable extending over this one pulley and downward intoengagement with a link of the section located therebelow whereby atensioning of the cable will effect at raising of the engaged link and acorresponding extension of the section and raising of the top frame.

5. A power lift comprising a base frame, a top frame in overlyingparallel relation to said base frame, an extension frame between saidbase frame and said top frame and mounting said top frame for verticaladjustment relative to said base frame, said base frame and said topframe including, in each instance, laterally spacedside members definingan open end for the reception of articles to be lifted therethrough andbetween the spaced side members, said extension frame comprising twosections, each section extending vertically between the correspondingside members of the base frameand the top frame and defining an openarticle receiving area between the side members of a constant depthdefined by the length of said side members,

a power unit mounted between the side members of the base frame opposedfrom the side member defined open end, said power unit being positionedtransversely between the base frame side members and including aselectively transversely extensible and retractable hydraulicallycontrolled piston rod, and force transmitting means engaged between thepiston rod and each extension frame for effecting a powered controlthereof and a selective raising and lowering of the top frame relativeto the base frame, said raising and lowering being effected withoutvarying the depth of the article receiving area between the sidemembers.

6. The lift of claim 5 wherein the force transmitting means comprises apair of cables fixed to the piston rod, each cable extending from therod to one extension frame section, and pulleys guiding each cable.

7. A power lift comprising a base frame, atop frame in overlyingparallel relation to said base frame, an extension frame between saidbase frame and said top frame and mounting said top frame for verticaladjustment relative to said base frame, said base frame and said topframe including, in each instance, laterally spaced side membersdefining an open end for the reception of articles to be liftedtherethrough and between the spaced side members, said extension framecomprising two sections, each section extending vertically between thecorresponding side members of the base frame and the top frame anddefining an open article receiving area between the side members, apower unit mounted between the side members of the base frame opposedfrom the side member defined open end, and force transmitting meansengaged between the power unit and each extension frame section foreffecting a powered control thereof, said power unit including aselectively extensible and retractable hydraulically controlled pistonrod, the force transmitting means comprising a pair of cables fixed tothe piston rod, each cable extending from the rod to one extension framesection, and pulleys guiding each cable.

8. The lift of claim 7 wherein one pulley associated with each cable ismounted adjacent the corresponding extension frame section generallycentrally thereof and at an elevated position relative to the baseframe, the associated cable extending over this one pulley and downwardinto engagement with a portion of the section located therebelow'wherebya tensioning of the cable will effect a raising of the section and thetop frame.

III t I t

1. A power lift comprising a base frame, a top frame in overlyingparallel relation to said base frame, an extension frame between saidbase frame and said top frame and mounting said top frame for verticaladjustment relative to said base frame, said base frame and said topframe including, in each instance, laterally spaced side membersdefining an open end for the reception of articles to be liftedtherethrough and between the spaced side members, said extension framecomprising two sections, each section extending vertically between thecorresponding side members of the base frame and the top frame anddefining an open article receiving area between the side members, apower unit mounted between the side members of the base frame opposedfrom the side member defined open end, and force transmitting meansengaged between the power unit and each extension frame section foreffecting a powered control thereof, each extension frame section beingof a scissor-type crossed link construction, said power unit including aselectively extensible and retractable hydraulically controlled pistonrod, the force transmitting means comprising a pair of cables fixed tothe piston rod, each cable extending from the rod to one extension framesection, and pulleys guiding each cablE.
 2. The lift of claim 1 whereinone pulley associated with each cable is mounted adjacent thecorresponding extension frame section generally centrally thereof and atan elevated position relative to the base frame, the associated cableextending over this one pulley and downward into engagement with a linkof the section located therebelow whereby a tensioning of the cable willeffect a raising of the engaged link and a corresponding extension ofthe section and raising of the top frame.
 3. The lift of claim 2including wheel means mounted on said base frame and depending therefromfor rolling engagement with the ground.
 4. A power lift comprising abase frame and a top frame in overlying parallel relation to said baseframe, an extension frame between said base frame and said top frame,said extension frame mounting said top frame for vertical adjustmentrelative to said base frame, said extension frame comprising a pair oflaterally spaced vertically orientated scissor-type crossed linksections, a power unit mounted transversely across said base frame, saidpower unit including a selectively extensible and retractablehydraulically controlled piston rod, and a pair of cables fixed to saidpiston rod for control thereby, each cable extending from said rod toone of said extension frame sections, and pulleys guiding each cablebetween the piston rod and section, one pulley associated with eachcable being mounted adjacent the corresponding extension frame sectiongenerally centrally thereof and at an elevated position relative to thebase frame, the associated cable extending over this one pulley anddownward into engagement with a link of the section located therebelowwhereby a tensioning of the cable will effect a raising of the engagedlink and a corresponding extension of the section and raising of the topframe.
 5. A power lift comprising a base frame, a top frame in overlyingparallel relation to said base frame, an extension frame between saidbase frame and said top frame and mounting said top frame for verticaladjustment relative to said base frame, said base frame and said topframe including, in each instance, laterally spaced side membersdefining an open end for the reception of articles to be liftedtherethrough and between the spaced side members, said extension framecomprising two sections, each section extending vertically between thecorresponding side members of the base frame and the top frame anddefining an open article receiving area between the side members of aconstant depth defined by the length of said side members, a power unitmounted between the side members of the base frame opposed from the sidemember defined open end, said power unit being positioned transverselybetween the base frame side members and including a selectivelytransversely extensible and retractable hydraulically controlled pistonrod, and force transmitting means engaged between the piston rod andeach extension frame for effecting a powered control thereof and aselective raising and lowering of the top frame relative to the baseframe, said raising and lowering being effected without varying thedepth of the article receiving area between the side members.
 6. Thelift of claim 5 wherein the force transmitting means comprises a pair ofcables fixed to the piston rod, each cable extending from the rod to oneextension frame section, and pulleys guiding each cable.
 7. A power liftcomprising a base frame, a top frame in overlying parallel relation tosaid base frame, an extension frame between said base frame and said topframe and mounting said top frame for vertical adjustment relative tosaid base frame, said base frame and said top frame including, in eachinstance, laterally spaced side members defining an open end for thereception of articles to be lifted therethrough and between the spacedside members, said extension frame comprising two sections, each sectionextending vertically between the corresponding side members of the baseframe and the top frame and defining an open article receiving areabetween the side members, a power unit mounted between the side membersof the base frame opposed from the side member defined open end, andforce transmitting means engaged between the power unit and eachextension frame section for effecting a powered control thereof, saidpower unit including a selectively extensible and retractablehydraulically controlled piston rod, the force transmitting meanscomprising a pair of cables fixed to the piston rod, each cableextending from the rod to one extension frame section, and pulleysguiding each cable.
 8. The lift of claim 7 wherein one pulley associatedwith each cable is mounted adjacent the corresponding extension framesection generally centrally thereof and at an elevated position relativeto the base frame, the associated cable extending over this one pulleyand downward into engagement with a portion of the section locatedtherebelow whereby a tensioning of the cable will effect a raising ofthe section and the top frame.